Welcome to Unearthed, an effort that will dig deep to try and figure out what’s true and what isn’t in the debate about our food supply.

“Debate” is a nice name for it. Sometimes it’s more like a melee — a meme-driven, name-calling free-for-all. Hackles, and voices, are raised. Rotten fruit is thrown. And all kinds of things pass for fact. Did you hear that Monsanto doesn’t serve genetically modified organisms (GMOs) in its cafeterias?

It’s not just genetic modification. We’re arguing about organics, honeybees, factory livestock, fishery depletion, aquaculture, yields, antibiotics, monocrops and chemicals. Some of these can be as polarizing as the most difficult social issues; there’s as deep a schism in the food community as there is in Congress. On the right, there’s the insistence that biotech is the only way to feed a growing population, and the reluctance to admit the shortcomings of industrial agriculture. On the left, it’s just the opposite. Monsanto, the avatar for Big Ag, is evil incarnate.

Unearthed is an attempt to negotiate the schism and nail down the hard, cold facts. The challenge is that, too often, facts are warm and slippery; evidence has a maddening way of being equivocal. Look at any current scientific question — any at all — and you can cherry-pick evidence to support the position you happen to like.

Case in point: the impact on human health of genetically modified crops, Unearthed Issue No. 1. Are they safe to eat?

There’s a great deal of research on the subject, but parsing the hundreds of studies done on GMO safety requires more time and expertise than most of us have. Instead, we look to someone else, someone we trust, to do it for us. And so the question of whether GMOs are safe becomes a very different question: Whom do you trust?

Most of us are already leaning one way or the other on GMOs, and it’s natural to trust the source we agree with. And there’s the problem. We talk to people who share our worldview (it’s a nicer word than bias), dig our heels in deeper and before you know it we’re shutting down the government.

To figure out how we all might make better decisions about charged issues, I talked with James Hammitt, director of the Harvard Center for Risk Analysis and a professor of economics and decision sciences. “Risks that are uncertain and dreaded tend to be more feared,” he said. GMOs are relatively new, poorly understood by many consumers, and in violation of our sense that food should be natural. Not only are those risks uncertain and dreaded, they’re visited on people trying to feed their families healthfully and safely while the benefits accrue to farmers and biotech companies. All of that adds up to an atmosphere that makes a reasoned debate difficult.

Reasoned debate requires that we weigh risk against benefit, and GMOs undoubtedly have both. Hammitt suggests looking for sources that discuss the trade-offs rather than just one or the other. The tip-off to your source’s, ahem, worldview? “If everything’s on one side of the ledger,” he says, “that’s a pretty good clue.”

So let me suggest a simple impartiality test: Does the person or organization you trust admit to both risks and benefits? If not, chances are good that your source has a dog — financial or ideological — in the fight. Read through Earth Open Source’s “evidence-based” position on genetically modified crops, “GMO Myths and Truths,” and you’ll find 123 pages of “no.” Go to GMO Answers, a Web site run by the biotech industry, and it’s hard to find any suggestion that there have been, or could be, disadvantages to genetic modification.

That doesn’t mean that either of those organizations is inevitably wrong. It’s just a tip-off that neither is impartial.

The impartiality exercise eliminates some of the organizations often cited in this debate. I couldn’t find the American Association for the Advancement of Science discussing GMO risks (although its journal, Science, does), and the Union of Concerned Scientists doesn’t talk about benefits.

The organizations I found that pass, though, form a compelling coalition. The National Academies, the American Medical Association, the World Health Organization, the Royal Society and the European Commission are all on the same side. Although it’s impossible to prove anything absolutely safe, and all of those groups warn that vigilance on GMOs and health is vital, they all agree that there’s no evidence that it’s dangerous to eat genetically modified foods. Even the Center for Science in the Public Interest is on board, and it has never been accused of being sanguine about food risks.

I’m not the first journalist to notice the consensus. Science-oriented publications including Nature and Scientific American have taken a hard look at safety and also concluded there’s no evidence that GMOs are bad for us. Nathanael Johnson, who’s doing yeoman’s fact-finding work at Grist.org, concurs.

There are dissenters, but I couldn’t find one that passed the test. Joining Earth Open Source and the Union of Concerned Scientists are the Non-GMO Project, the Center for Food Safety, the Institute for Responsible Technology, the American Academy of Environmental Medicine and GMWatch.

The relative clarity of this issue exposes deep fissures in the debate. Read an article on GMO safety and you’re almost guaranteed to find that the comments section comes to virtual blows. The anti-GMOs call the pro-GMOs Monsanto shills. The pro-GMOs call the anti-GMOs anti-science Luddites. And that’s over an issue where the science is fairly clear! When we get into areas where the evidence is more equivocal, what hope can there be?

The Earth has 7 billion people to feed, and we need to figure how to do it efficiently, affordably and responsibly. Can we make this discussion more constructive?

NYU psychology professor Jonathan Haidt might be able to help. His recent book, “The Righteous Mind: Why Good People Are Divided by Politics and Religion,” describes the two ways we humans look at issues: “We effortlessly and intuitively ‘see that’ something is true, and then we work to find justifications, or ‘reasons why,’ which we can give to others.” His metaphor is that our intuitive understanding is an elephant, and our reasoning is the rider. The GMO debates features riders sparring about research methodology, gene insertion techniques and mutagenicity while our elephants, responding instead to a gut-level moral sense, go placidly along their chosen route.

It’s hard to wrangle elephants, our own or other people’s, but we can start by trying to understand motives. Talk to a biotech opponent and you might find his opposition rooted in fear that GMOs are compromising the variety and long-term viability of our food supply. Talk to a biotech backer and you might find her support based on the promise that GMOs show for increasing the efficiency and nutrient levels of our crops. Surely there’s enough common ground there to start a discussion.

Elephant wrangling, like charity, begins at home. I find it takes effort to compensate for my elephant’s affinity for biotech. It took me a while to understand that, if you believe that GMOs are contributing to monocrops, endangering small farmers, entrenching industrial agriculture, laying waste to the environment and securing corporate admittance to the corridors of power, it’s hard to see the point of parsing the evidence on human health. Although I don’t hold with all of that, I don’t think anyone can, in good faith, dismiss it out of hand. And so I think we should talk.

Here at Unearthed, I’d like to do that. I’ll be trying to get at the facts, without losing sight of the context in which we process those facts. I welcome participation: Express your opinion in online comments, respond to someone else’s (or to mine), ask a question, suggest a topic. The goal is constructive engagement. The rule — the only rule — is civility.

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Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.